Robotic devices have been used in industrial settings to automate repetitive manufacturing processes such as automobile assembly and semiconductor manufacturing. However, these industrial robots are often complex and expensive. As the use of robotic devices becomes more common in non-industrial settings such as homes, offices, small businesses, and universities, it becomes increasingly important to design robotic devices that are capable and robust while at the same time affordable enough to use in such settings. The mechanical design of robotic devices may be simplified to minimize the cost of manufacturing the devices and decrease the complexity of the control system required to control the devices.